More tips that should be helpful:
1) Always scout your opponents each sim week. I look at play use over the previous 4-8 weeks to get a good average, and then I always look at the plays the prior week to see what they attempted on the last opponent.
2) The Coach's playbook matters because there are some playbooks that do not have the most effective plays, leading to:
3) The game is fairly "broken" at this point and most longtime users select the same 15-20 plays for maximum effectiveness. I use about 30 plays on Offense and 20 plays on Defense. This avoids any overuse penalties (the script during the sim says, "The O or D better start mixing things up or there will be more plays like this." If the same play is called continually, it will ineffective or detrimental.
3) Defensively, invest in speedy man coverage players and B/R avoidance. Don't play deep zone because no one can throw deep. Select defensive plays that aim to cover man-to-man and within 10 yards. I choose a lot of 1 man deep, 1 LB blitz and everyone else is man. A solid defense is surprisingly helpful to ensure you keep scoring points on offense.
4) Ball control is important! You need a balanced team. If I had my way, I would aim to control the ball 40 min + on offense, convert at least 50% on 3rd downs (tougher than you think).
5) Steal ideas religiously from the forums, from other players. Use the scouting to get an advantage and see what others are doing. Look through the game logs of the league's best players and see what plays they're using, coach's playbook, which players are getting the targets (is it the same fast WR running a TE route [then they're overriding that player on the depth chart, a whole other thing] or are they checking it down to a RB out of the flat [you have to have your fastest CB/FS to cover that player out of the backfield or they will keep doing it]?),